Stable anti-rust lubricating oil



"using synthetic sea water.

United States fiatent No Drawing. Application December 1, 195 Serial 151015505504 This invention relates, to a stable anti-rust lubricating oil' composition containing certain epoxyalkaneamine reaction products which is' characteriied by its ability to P 1 1 4 est s g a ed s ASTM'='D665 T nd als by ts g o ep a on characteris c in h etents b l y, test es gnate as STMI U T, he res l being expressed as .ASTM Steam Emulsion Number (8'. E. N01 These t ar ll, known n idely sed n w hereinafter e erred] to as the t at test an steam emulsion number.v

,The protection of metallic-equipment from rusting has I been a problem of. long standing. A partieularly acute problem has been the prevention of the rusting of ferrous parts operating inv an environment wherein water from various sources mixes with the lubricant as in steamturbine oils. Passage of'the'rust test, ,as above designated, 1s, one of the critical factors iuthe formulation of satisfactory steam-turbine oils. For this purpose, there are I available various. rust inhibitors which; have difierent'de- E s fi'hc eness It has been found that even among inhibitors of the same generic class there is a wide variation in ability to carry a formulation through the rust test. In particular, it has been found that only certain amino-alcohol compounds are effective for. this purpose.

Previous independent experiments on a number of rust inhibitors and related polymers had indicated that if the addend failed to pass the ASTM-D665 Rust Test, method A using distilled water, it also failed themethod B test included the co-polymers of styrene oxide and such materials, as propylene sulfide, Z-mercaptopropyldibutylamine and -hY YP PY dihu ylam n The materials: failed the ASTM D565 Rust Test (method A) when used in amounts ranging from Q-QS" to 2.0 weight percent. It was also found that, other amin c mpou d such as tetramethyldiaminodiphenylmethane, dibutyl amine, triamylamine, aniline, methylaniline, dimethylaniline, r nzyl mine, and. t e h m n wh n t s in amounts ranging from O1 to 0,5 weight percent in a base oil were ine fec i in pa ng h rust test- In addition, it has been discovered that certain. inhibitors, though v 3, eifective in their ability to prevent rusting,c1 nn0t be used because of emulsification and/ordecreased stab ity of he compos on, n e pr of steam. For example, compounds such as tris (hydroxymethyl) aminomethane, although an elfective rust inhibitor, was also an excellent emulsifying agent and could not be used because of emulsibility troubles. My invention resides in the discovery that amino-alcohols, not only are excellent rust inhibitors but also do. not adversely affect the demulsibility or steam emulsion number of the composition as, do other related members of the class.

' Accordingly, it is a primary object of my invention to provide a composition for inhibiting the rusting of metalli surfa s.

Another object of the invention is to provide a rustinhibiting composition of matter exhibiting; resistance to emulsion in the presence of water;

I Still another object is to provide a stable antirust lubrieating oil composition containing certain amino-alcohols.

Some of the addends tested 2,856,363 Pa ented Qct- 1 ,1958

ice

2 A furth bject at t e nventi n s to pr i a stabl anti-rust lubricating oil composition containing certain ammcal hcls prepared: y the condensa no r ction o c r a n alkanolamin ith. p xy l e A therobjectis o. provide.- a. s m-tur ine 0 1. ompo o s con ai ng among: other ingredi nts a sma amo n of. at as 'ue f theab ed fihed m n -alcohol c.sntu cuz ds which-is. ch acterized by ts ab li y t pas the ru t tes andwhi h h hi sa satisfac ry tea emulsion number as herein defined.

These and o h r obj c s f my invention i h de scribe or beco e app rent as the. des ption her of Proceeds Q B oa fly he. inhib t ot the pres t.- in nticn. c mp is th reaction p odu s of en xyalkan s and m n alkauclamiu or dialkan lamiries- A tho gh. poxyalkan smay econdqhs d wit alky am nes r t riethahol m nes, uch eact on p uc s, are not su t-able rust inh bi or h gen ral .r ac onforming the am n alcohol nhibitorsof his invent on m y he ep es nte as fo ows: i

i Q 7 Y Q ti hi' cn Eporyalkane- Alkanolamine Amlnoaloohol wherein R is an 'alkyl' group having from '2 to 12- carbon atoms', R"1nay'be hydrogen 'or an alkyl group- 0132 to 1-2 carbon atflms, R is a hydrocarbon chain having from 2 to 5 carbon atoms and Y- may comprise hydrogen or another f"OH grouping. R" may carry methyl substituents to increase the oil solubility. Specific examples are the condensation product of 1,2-epoitydodecane and and monoethanolamine and the condensation product of- 1,2 epoxyydodecane and diethanolamine; These compounds have the formulae e1wnzwcnouecnwuuacazcnaoa and aredesignated for purposes of the claimed: invention as Z-hydroxy dodecane-l monoethanolamine and 2. bydroxy dod'ecane-l-diethanolamine.

The epoxyalkanes used in preparing the aforementioned amino-alcohols are selected from a; Wide group of stright chain epoxy compounds known and used in or ganic synthesis. The epoxyalkanes are prepared by reaction of an unsaturated aliphatic hydrocarbon, having its double bond either between the terminal carbon atoms of the chain or located between carbon atoms which are located within the middle portion of the carbon chain, with hypochlorousacid, by oxidation, or by epoxidation. In the reaction with hypochlorous acid the chlorohydrin derivative isformed in the first step, and is transformed to=the epoxide by dehydrochlorination with an alkali, such as sodium hydroxide. In each reaction theresult is the placement of a single oxygen atom across the double carbon atom bond.

The epoxyalkanes include the epoxides of the follow.- ing unsaturated aliphatic hydrocarbons:- buteneal, pentene-l, hexeneal, hcp'tene-l, octene-l, nonene-l', decene-l, undecene-l and dodecene-l as the aliphatic olefi ns, where:- in a single oxygen atom is linked across" adjacent carbon atoms at the double bond. The various structural isoimers of these, wherein the- Y H H T/ group and the amino group are at opposite ends of the molecule.

The reaction by which the alkanolamine and the epoxyalkanes are condensed is very simply carried out, since no catalysts or solvents are. required. According to Huscher and Long in United States Patent 2,602,819,

in using the lower molecular weight epoxyalkanes it is only necessary to place the alkanolamine, in anhydrous condition, into a reaction vesselfitted withcoolingmeans and slowly add the epoxyalkane. The rate of addition .of the epoxyalkane is used to control the reaction temperature. Since the epoxyalkane may be lost by evaporation it is advisable to conduct the reaction under reflux or in a closed vessel at a pressure at least equal to the autogenous pressure of the reaction mixture to prevent such loss. The pressures used do not generally exceed 2-3 atmospheres. The reaction proceeds rapidly and is completed within a few-hours, at the most, after theaddition of the epoxyalkane is finished. Evolution of heat ceases upon completion of the reaction. The reaction temperature, which may start at 0., should be controlled to avoid exceeding about 100 C. in order to prevent the formation of undesirable lay-products. The reaction of 20 gram-mols of propylene oxide with gram-mols of monoisopropanolamine takes place at room temperature in a closed vessel to form a predominance of tri-isopropanolamine.

Usually, the proportion of epoxyalkane to alkanolamine used will be no more than 2:1 when the reactant is monoalkanolamine and not more than 1:1 when the reactant is dialkanolamine. For the reaction of higher molecular weight epoxyalkanes having from 6 to 12 carbon atoms, the reaction may be carried out by the method described in United States Patent 2,373,199 by subjecting a molecular excess of a mono-alkanolamine to reaction with an epoxyalkane at higher temperatures, between 120 to 275 C., under pressures up to 1000 pounds per square inch. Reaction of 6 gram-mole of monoethanolamine with 1 gram-mol of ethylene oxide at 150" C. and 485 pounds per square inch pressure, using the U. S. 2,373,199 method, results in a 78% conversion to monoethyl amino ethanol and a 19.6% conversion to monoethyl diethylolamine.

The epoxyalkane-amine reaction products of this invention are not to be confused with the high molecular weight polymeric materials formed in accordance with such prior art processes" as disclosed in United States Patents 2,522,155 and 2,498,195 by Ballard, Morris and Van Winkel, or the products of the process ofUnited States Patent 1,920,578 by Schoeller and Wittwer. These condensation products have a plurality of (0R)- groups in the molecule and are of high molecular weight and polymeric in nature.

In order to demonstrate the invention, a number of steam-turbine oil compositions were prepared from a base oil composition which contained the following ingredients:

Table I Wt. percent Mineral oil 99.518 Paranox 441 0.35 Age Rite Stalite 0.12

Butyl zimate 0.012

The mineral oil was composed of 27 wt. percent of Mid-Continent, solvent-refined neutral oil which had the following characteristics: viscosity at F., 82.1 SUS; viscosity at 210 F., SUS 37.9; 103 V. I.; C. R., con., percent, 0.00; flash, COC, F., 390; fire, COC, F., 425; gravity, API, 35.5; pour, ASTM', F., 0.00; and 72.51 wt. percent of Mid-Continent, solvent-refined neutral oil which had the following characteristics: carbon residue (Conradson), 0.01%; flash, COC,.415 F.; fire, COC, 480 F; API gravity, 31.3;'pour, 0 F.; viscosity at 100 F., SUS, 178; viscosity at210 F., SUS, 46.2; and a V. I. of 100. This composite *baseoil had a carbon residue (Conradson) of 0.01%; flash, COC, 400 F.; fire, COC, 455 F.; API gravity,32.8; pour, 0 F.; viscosity at 100 F., 148 SUS; viscosity at 210 F., 43.1, SUS. Paranox 441 is a trade name for'di-tertiary-butyl paracresol and is present in the composition. for the purposeof inhibiting oxidation. Cresols generally, and especially this specific cresol,have no measurable ability to either inhibit or promote the formation ofrust. Age Rite Stalite is a trade name for a. mixture of'octylated and styrenated diphenylamines. This aryl amine product is incorporated for the purposeof inhibiting oxidation, and has no particular' anti-rust or rust p'roducing properties in itself. Butyl zimate is a zinc dibutyldithiocarbamate and is used for the purpose of inhibiting oxidation. The combination of these three materials is a synergistic mixture for inhibiting oxidation.

, The base composition may be varied somewhat from the weight percentages shown above. Up to 1.0 wt. percent of Paranox 441 inaybe used, depending upon the level of oxidation. stability required or desired. The

Age Rite Stalite may be present in'amounts ranging up to 0.5 wt. percent, as long as a sufiicient amount is present to adequately inhibit oxidation. Similarly, the butyl zimate may be used in amounts ranging up to 0.05 wt. percent.

Threedifierent epoxyalkane-amiue reaction products were used in these tests and the ability of equal amounts of these materials to inhibit rusting was evaluated. The results are shown in the following Table II:

Blend Composition, Percent Wt.

Base Composition 1, 2Epoxydodecane-dibutylamlne 1, 2 Ep xydod( cang.mnnnnthnnnlam a 1, 2-Epoxydodecane-diethanolamine It is seen from the above experiments that the epoxyalkane-alkanolamine reaction products were effective rust inhibitors in'comparison to the unsatisfactory epoxyalkane-alkylamine product, and that. the epoxyalkanemono-alkanolamine product was the more effective for both distilled and sea water at theconcentration level shown. Both of the preferred compounds give a satisfactory Steam Emulsion No. for the oil. The blank oil had a Steam Emulsion Number of 40.

The condensation product of 1,2-epoxydodecane and monoethanolamine was prepared by reacting 14 parts of the epoxide with 18 parts of monoethanolamine by refluxing the materials for 4 hours. The dibutylamine and diethanolamine reaction products were similarly prepared; From this it is seenthat the monoethanolamine reaction product is superior to the dibutylamine and diethanolamine reaction products in rust inhibiting properties. Effective concentrations of the alkene expoxide- 3 uct finds its usefulness in those applications where the coolant water that may contaminate the lubricant is land water. The 1,2 epoxydodecane-monoethanolamine product extends the usefulness to use aboard ship, for example, where sea water contamination presents a serious corrosion problem.

What is claimed is:

1. A lubricating oil composition characterized by its oxidation stability and its ability to pass the ASTM-D665 Rust Test, comprising a major amount of mineral lubricating oil, an oxidation inhibitor combination comprising about 0.35 weight percent of di-tertiary butyl paracresol, about 0.12 weight percent of a mixture of octylated and styrenated diphenyl amines, about 0.012 weight percent of zinc dibutyl-dithiocarbamate, and about 0.01 to 0.5 weight percent of an amino-alcohol having the general formula:

wherein R is an alkyl group having from 2 to 12 carbon atoms, R is selected from the group of hydrogen and an alkyl group of 2 to 12 carbon atoms, R" is a hydrocarbon chain having 2 to 5 carbon atoms and Y is selected from the group of hydrogen and an "OH group.

2. A lubricating oil composition in accordance with claim 1 in which R is an alkyl group having carbon atoms, R is hydrogen, R" is a hydrocarbon chain having 2 carbon atoms and Y is hydrogen.

3. A lubricating oil composition in accordance with claim 1 in which R is an alkyl group having 10 carbon atoms, R is hydrogen, R" is a hydrocarbon chain having 10 carbon atoms and Y is hydrogen.

4. A lubricating oil composition in accordance with claim 1 in which the amino-alcohol is Z-hydroxy dodecane-l-diethanolamine.

5. A lubricating oil composition in accordance with claim 1 in which the amino-alcohol is a 2-hydroxy dodecane-l-monoethanolamine.

6. A steam-turbine oil comprising about 25 volume percent of 85 viscosity neutral oil and 74.46 volume percent of a 175 viscosity neutral oil, about 0.35 weight percent of di-tertiary butyl para-cresol, about 0.12 weight percent of a mixture of octylated and styrenated diphenyl amines, about 0.012 weight percent of zinc dibutyl -dithiocarbamate and about 0.05 weight percent of 2-hydroxy dodecane-l-diethanolamine, said composition being characterized by its ability to pass the ASTM-D665 Rust Test.

7. A steam-turbine oil comprising about 25 volume percent of viscosity neutral oil and 74.46 volume percent of a viscosity neutral oil, about 0.35 weight percent of di-tertiary-butyl para-cresol, about 0.12 weight percent of a mixture of octylated and styrenated diphenylamines, about 0.012 weight percent of zinc dibutyldithiocarbamate, and about 0.05 weight percent of 2- hydroxy dodecane-l-monoethanolamine, said composition being characterized by its ability to pass the ASTM- D665 rust test.

8. A lubricating oil composition characterized by its ability to pass the ASTM-D665 Rust Test, comprising a major portion of a mineral lubricating oil containing about 0.35 weight percent of di-tertiary-butyl para-cresol, about 0.12 weight percent of a mixture of octylated and styrenated diphenylamines, about 0.012 weight percent of zinc dibutyl-dithiocarbamate, and about 0.05 weight percent of 2-l1ydroxy dodecane-l-monoethanolamine.

9. A lubricating oil composition characterized by its ability to pass the ASTM-D665 Rust Test, comprising a major portion of a mineral lubricating oil containing about 0.35 weight percent of di-tertiary-butyl para-cresol, about 0.12 weight percent of a mixture of octylated and styrenated diphenylamines, about 0.012 weight percent of zinc dibutyl-dithiocarbamate, and about 0.05 weight percent of Z-hydroxy dodecane-1-diethanolamine.

References Cited in the file of this patent UNITED STATES PATENTS 2,497,553 Long Feb. 14, 1950 2,522,155 Ballard et al Sept. 12, 1950 2,602,819 Huscher et al. July 8, 1952 2,605,224 Jahn July 29, 1952 2,629,694 Woods et a1 Feb. 24, 1953 

1. A LUBRICATING OIL COMPOSITION CHARACTERIZED BY ITS OXIDATION STABILITY AND ITS ABILITY TO PASS THE ASTM-D665 RUST TEST, COMPRISING A MAJOR AMOUNT OF MINERAL LUBRICATING OIL, AN OXIDATION INHIBITOR COMBINATION COMPRISING ABOUT 0.35 WEIGHT PERCENT OF DI-TERTIARY BUTYL PARACRESOL, ABOUT 0.12 WEIGHT PERCENT OF A MIXTURE OF OCTYLATED AND STYRENATE DIPHENYL AMINES, ABOUT 0.012 WEIGHT PERCENT OF ZINC DIBUTYL-DITHIOCARBAMATE, AND ABOUT 0.01 TO 0.5 WEIGHT PERCENT OF AN AMINO-ALCOHOL HAVING THE GENERAL FORMULA: 